Control of fuel injection engines



Aug. 17, 1,943.A Y

A. F. SANDERS 2,326,888

CONTROL OF FUEL INJECTION ENGINES Filed Aug. 7, 1941 fic. 5.

'y ..1[79L I 7 Patented Aug. 17, 1943 UNITEDv STATES PATENT OFFICE coN'rRoL or FUEL mmc'rloN ENGmr-:s

Arthur Freeman Sanders, vLeeds, England, as.

signor of one-half to John Fowler t Co. (Leeds) Limited, Leeds, England Application August 7, 1941, Serial No. 405,880

f y In Great Britain April 5, 1941 t 9 Claims. (Cl. 12S-140) 378,668 led February 12,1941.

The invention will best be understood if consideration be made to the following description, in which reference is made to the accompany ing drawing.

In the accompanying sheet of drawings:

Figure 1 is a sectional elevation of a preferred construction of governor according to the invention, the figure showing in elevation a portion of the associated fuel pump.unit and of a driving gear for the governor;

Figure 2 isa cross-section (omitting certain parts) taken mainly on the line II-II of Figure 1, showing one method of connecting an yidlingcontrol sleeve of the governor with a fuel control rod of the pump unit; and

Figure 3 is an elevation showing bellcrank lever by means of which atimingcontrol gear of the governor can be actuated either by a thermostat or manually.

In the drawing II represents a part of a fuel pump unit which may be of known form, I2 beingy an endwise-located spindle by which the pumps of the unit are actuated, and I3 a fuel control rod the remote end (not shown) of which can beengaged by a main control `to vary the quantity of fuel injected per stroke and thereby the speed at which the engine supplied by the pump unit will run for a given load. The pump spindle I2-is driven at a speed responsive to that of the crankshaft of the engine, the pump spindle having slidably splined upon it' a timing-control gear I4 in mesh with a driving gear I5 which is continuously driven from the engine cranka three-armed l left will vary the angular position of the spindle l2 with respect to the engine crankshaft and will thus vary the moment of injection, as will be well understood. The teeth of the driving gear I5 are sufficiently wide for the teeth of the gear I4 to remain in mesh therewith when the gear I4 is thus moved to the left from the stationary position shown.

The governor weights I9 are pivotally mounted at 20 upon brackets of a sleeve 2| which is end` wiseY and rotatively fast on the pump spindle I2, and they coact with the adjacent radial face of an idling-control sleeve 23 which is slidably' keyed upon the sleeve 2l and is urged to the right (Fig. 1) by a relatively-light governor spring 24. When the parts are stationary (as shown) there is clearance, indicated at 25, between the timingcontrol gear I4 and the idling-control sleeve 23, this clearance being mainly, but not entirely, taken up by the movement of the 'idling-control sleeve to the left when the engine is idling and the weights I9 are in the corresponding idling position. When the main control is opened uptov speed up ,the engine the clearance is entirely shaft. In the present instance the gears I4 and I5 have helical teeth, as is shown in connection with the gear I5, which latter is axially fast. The timing-control gear I4 is biased to the right (Figure 1) against a stop, shown as a circlip I6 on the spindle I2, by means of a'main governor spring Il. Movement of thegear I4 to the taken up by the outward movement of the Weights, this forcing the idling-control sleeve to the left and also causing the timing-control gear I4 to move to the left to advance the moment of injection, and vice, versa. `In this way the moment of injection is controlled responsively to the engine speed, being earlier at high engine speeds than at low engine speeds, and being set at a minimum late value while the engine 1s idling. i

, As disclosed in the patent specification accompanying the co-pending patent application above mentioned, it is desirable when the engine is cold, and possibly in other conditions also, that the moment of injection should be advanced independently of the governor action. In the presl ent instance the timing-control gear I4 is shown engaged by an actuating fork 29. This may-be formed with a projecting pin (not. shown) engaged with the` arm A3| of the bellcrank lever shown in Figure 3, rather in the manner of the fork hereinafter disclosed in connection with Figure 2. The bellcrank lever has two other arms on the common shaft 33 one of which is a short arm 34 connected to a rod 35 leading' to a thermostat (not shown). ,The parts are shown in the position in which the timing ,is fully retarded, as when the thermostat is hot and the engine stationary or idling. When the thermostat cools down it pulls up the arm 34 to the position indicated by the chain line 34a, to

advance the timing, this action of the thermostat sliding the timing-control gear to the left in a slot in the end of the rod 35, whereby manual actuation of the arm 31 will not interfere withthe thermostat when this is warm. In this way the governor'action can be overriddeu either automatically or manually, as required.

The specification above mentioned also describes a method by which a governor, which can be overridden, for controlling the moment of injection can also control the running of the engine when idling, the governor being in that case connected to the fuel control rod I3 by means of a resilient lost-motion device which is, however, sufficiently weak so as not to interfere with the governor action to any material extent when the fuel control rod is manually actuated. Figure 1 shows a substantially similar arrangement, 4I indicating a resilient device consisting of a tube 42 in which works a plunger 43 fast with the fuel control I3. A circlip 44 prevents the withdrawal of the plunger which is engaged by a compression spring 45 in the interior of the tube. A bracket 46 connected to the other end of the tube is in turn connected to one arm of a bellcrank lever 48 the other arm of which engages a pin 49 on a fork 5| engaged with the idling-control sleeve 23.

'Ihe governor springs have a differential effect, as described in the specification aforesaid,

asees angular advance or retard of said spindle'with reference to said driving part.

3. The combination with a variable-speed, fuel-injection engine, of a speed-responsive governor, the governor including a driving part driven from the engine, an endWise-located spindle, a. fuel pumping unit driven from said spindle, a spring-pressed axially-slidable part in the drive from said driving part to said spindle, said axially-movable part having a screwthreaded engagement with said driving part, and a second axially-movable part which has a small endwise clearance from the first-mentioned axially-movable part when the engine is idling and which is axially positioned by the governor Weights whereby except when the engine is idling said first-mentioned axially-movable part will be axially positioned by the governor weights to cause the angular advance or retard' of said spindle with reference t0 said driving part, and

`a fuel control rod for the pumping unit, said second-mentioned axially-movable part being connected to said fuel control rod by means of a spring so as to control the speed of the engine when idling, said spring being weak compared with the governor spring so as to not materially affect the governor action when the engine is 0D- erating in excess of idling and the fuel control rod is being manually actuated.

4. The combination with a lvariable-speed, fuel-injection engine, of a fuel pump, an end- Wise-fast spindle for operating said pump, a

speed-responsive governor having bob-Weights and the manner in which the idling of the engine is controlled will be readily understood from a consideration of that specification.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. The combination with a variable-speed, fuel-injection engine, of a speed-responsive governor driven from the engine, the governor including an endwise-located spindle, a fuel pump driven by said spindle, an axially-movable part in the drive from the engine to said spindle, a driving part, said axially-movable part being positioned axially by the governor weights and having a screw-threaded engagement with said driving part whereby said spindle will be angularly advanced or retarded with respect to the engine dependently upon the position of the governor weights,and manual and automatic means also connected to said part so that the latter can be positioned axially thereby independently of the governor action.

2. The combination with a variable-speed, fuelinjection engine, of a speed-responsive governor, the governor including a driving part driven from the engine, an endWise-located spindle, a fuel pumping unit driven from said spindle, a springpressed axially-slidable part in the drive from said driving part to said spindle, said axiallymovable part having a screw-threaded engagement with said driving part, and a second axiallymovable part which has a small endwise clearance from the first-mentioned axially-movable part when the engine is idling and which is axially positioned by the governor weights whereby except when the engine is idling said firstmentioned axially-movable part will be axially positioned by the governor weights to cause the and a main spring, said governor driven from saidspindle, a gear having a sliding and driving connection with 4said spindle, an axially movable part which hasa small endwise clearance from said gear when the engine is idling, said gear positioned axially by said spring and bob-Weights when theengine is operating in excess of idling, and a second gear drivenfrom the engine, said gears meshing with one another and. having helical teeth.

5. The combination with a variable-speed, fuel-injection engine, of a fuel pump, an endwise-fast spindle for operating said pump, a speed-responsive governor having bob-weights and a main spring, said governor driven from said spindle, an axially movable part which has a small endwise clearance from said gear when the engine is idling, a gear having a sliding and driving connection with said spindle, said gear positioned axially by said spring and bob-Weights when the engine is operating in excess of idling,

' a second gear driven from the engine, said gears meshing with one another land having helical teeth, and means for sliding said first gear independently of the governor action.

6. The combination with a variable-speed, fuel-injection engine, of a fuel pump, a spindlev for operating said pump, a slidable rod for controlling the fuel-supply of said pump, driving means for said spindle including a meshing pair of helically-toothed gears one of which is axially movable, an axially movable part which has a small clearance from. the axially movable gear when the engine is idling, a speed-responsive governor driven from said spindle, said governor having bob-Weights and a mainpspring adapted to act upon said slidable gear, at speeds in excess of idling speeds of the engine, to position it axially and thus vary the moment of injection, and means whereby when the engine is idling said governor will act upon said slidable rod to govern the quantity of fuel supplied.

7. The combination with a variable-speed, fuel-injection engine, of a fuel pump for the engine, an endwise-fast spindle for operating the pump, a slidable rod for controlling the fuel delivery oi the pump, driving means for the spindle including a gear pair having helical meshing teeth, the driven gear thereof being slidably keyed on the spindle, a main governor spring urging said slidable gear axially against a stop,` governor weights rotatable with the spindle, a sleeve freely mounted on the spindle moving said slidable gear axially, whereby to the combination with a fuel pumping unit havto be moved axially by said governor weights,

ing a driving shaft, of a speed-responsive governor associated with said driving shaft such that the moment of injection 'will be later at low engine speeds than at higher engine speeds, and of manual and automatic means for Varying the governor action, the automatic means being such that, when the engine is cold, the moment of injection will be earlier than when normal temperatures have been reached, for a given enlgine speed, said governor comprising a spirallytoothed gear which is driven at a speed dependentupon that of the engine, said gear having a sliding and driving connection with said driving shaft, said driving shaft being endwise located, whereby the timing of the fuel pump is controlled on the axial movement of the said gear, the latter being positioned axially by the governor weights and the main governor spring.

ARTHUR FREEMAN SANDERS. 

